According to Jan Norbye, writing in SIA #32, January-February 1976, the most successful OEM application of superchargers (at least to date) was the Graham-Paige’s in the 1930s, with more than 15,000 sold. Wethinks that may require some additional research, but the rest of the article holds up pretty well, with a brief but informative explanation of the different types of superchargers and how they actually stuff more air into a car’s engine.